Mildewproofing and mothproofing treatment



Patented July 7, 1942 MILDEWPRDOFING AND MOTHPROOFIN G TREATMENT MartinLeatherman, Hyattsviile, Md.

No Drawing. Application March 22, 1941, Serial No. 384,699

Claims. (Cl. 8-1365) (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) This application is made underthe act of March 3, 1883, as amended by the act of April 30,1928, andthe invention herein described and claimed, if patented, may bemanufactured and used by or for the Government of the United States ofAmerica for governmental purposes without the payment to me of anyroyalty thereon.

This is a'continuation in part of my co-pending application for patent,Serial No. 242,124, filed November 23, 1938, which issued April 15,1941, as Patent No. 2,238,850.

This invention relates to mildewproofing of fabrics which are used incontiguity with rubber, such as cotton hose lined with rubber, beltings,raincoats, rubberized shower curtains, rubber elasticized fabrics, andso forth. This invention also relates to a combination of mildewproofingand-mothproofing for plant and animal fibre fabrics subject to thedestructive action of fungi or insect larvae, such as wool, cotton,silk, mohair, and so forth.

One of the objects of this invention is to provide mildewproofing meanswhich are colorless and which will not be readily removed by theordinary so-called dry cleaning solvents or by water.

Another object of my invention is to provide substances which possesshigh mildewinhibiting power and which may be used in close associationwith rubber without any deleterious effect upon the rubber.

Heretofore copper has been the most common,

mildewproofing metal, but it is unsatisfactory when used in rubberizedfabrics because it induces changes in the rubber component and also thecopper is absorbed by the rubber with resulting destruction of itsmildewproofing action. I have discovered that cadmium has no injuriouseil'ect whatever upon rubber, and that it is approximately twice aseffective as copper in inhibiting growth activity of organisms incellulose. The action of the cadmium is inherent and is exertedregardless of the type of compound in which the cadmium is bound, andwithout regard to the solubility of the compound. Since the very solublecompounds will be more readily removed by exposure to water action, Iprefer to.

use relatively water-insoluble compounds of cadmium in practicing myinvention, but I may also use soluble compounds such as cadmiumchloride, cadmium sulfate and the like. Among the relatively insolublecompounds I may use cadmium pentachlorophenate, cadmium naphthenate,cadmium ortho-phenylphenate, cadmium carbonate,

cadmium hydroxide, cadmium oxide, cadmium orthophosphate, cadmiumsilicate, cadmium chloro-ortho-phenylphenate, cadmium2,4,dichloroortho-phenylphenate, and cadmium2,4,dibromo-ortho-phenylphenate. In general, the types of cadmiumcompounds which can be used, both organic and inorganic, are thosewhich, under the moist conditions associated with fungus growth, yield asuflicient amount of cadmium ions to exert their inhibiting effect uponfungus growth.

The method of treating the material is by the usual metatheticalreactions employed to deposit precipitates on fibrous materials whichcomprises either (1) first wetting out the materials with awater-soluble salt of cadmium of the desired concentration, drying, andthen wetting with a'solutlon of the precipitant or (2) first wetting outthe materials with a solution of the precipitant, drying, and thenwetting with a solution of the cadmium salt, respectively. For example,if it is desired to introduce cadmium carbonate, the fabric is firstwetted with a solution of, for example, cadmium chloride, dried and thenimmersed in a solution of sodium carbonate. This order of procedure willordinarily be preferred to the reverse order when inorganic compoundsare being deposited on cellulosic materials.

The common fatty acid soaps of cadmium such as the oleate, palmitate,and stearate may also be used. These soaps are practically insoluble insuch solvents as carbon tetrachloride, gasoline, Stoddards solvent, andsolvent naphtha. is not true with respect to the non-fatty acid soaps,such as the resinate, which are very soluble in these solvents. For thisreason, fabrics treated with the fatty acid soaps of cadmium may be drycleaned, whereas the non-fatty acid soaps of cadmium would be removedfrom fabrics by dry cleaning, although mildewproofing action is obtainedin both cases.

I have found that five-hundredths of one percent of cadmium by weight issufficient, even in the caseof the most insoluble compounds, such as thefatty acid soaps, to prevent mildewing of cellulose fabrics. Anillustrative method of treating the fabric with an insoluble soap inaccordance with my invention comprises saturating the fabric with asolution of ordinary alkali soap of sufficient concentration to fixapproximately fivehundredths of one percent of cadmium by weight, thencedrying the fabric, and then immersing it in a solution of a cadmium saltas a precipitant, such as the chloride, which solution preferably Thiscontains a wetting agent, suchas sodium lauryl sulphate, for example.The fabric. is then washed. If desired, it may also be treated with asolution to precipitate the wetting agent. When using sodium laurylsulphate as the wetting agent, a solution of a potassium salt may beused for this purpose. The fabric is then dried. By treating the fabric,before the first drying step in the method described above is quitecompleted, with a solution of silicofiuoride both mildewproofing andmothproofling is eflected and the remaining steps in the process may beomitted, since this solution precipitates the cadmium soap in thefabric. The fabric being somewhat damp, it absorbs sumcient cadmiumfiuorsilicate solution to precipitate the soap compound, leaving aresidue of cadmium soap and alkali fluosilicate in the fabric.Fluosilicates are of value for mothproofing, and the waterproofingeffect of the cadmium soap prevents easy removal of the residualwater-soluble cadmium and alkali fluosilicate except by prolongedexposure to water. Fluosilicate would not be employed except in the caseof cellulosic materials which are mixed with animal fibers such as wool.

The cadmium soap may also be-introduced into the fibrous material bymaking use of certain mixed solvents to dissolve the soap and carry itinto and through the fibrous material. For example, the cadmium soap canbe dissolved in a hot solution of a solvent consisting of two partsbenzene, one part acetone, and one part methanol by volume. one,especially when warm, retain enough cadmium soap in solution to permitthe introduction of the soap into the material to be treated by wettingit with the solution and then drying the fabric.

Cadmium fiuosilicate may also be used by itself to effect a combinationof mildewproofing and mothproofing. Being soluble in water, but not inorganic solvents, it may be employed in the home to temporarily protectwashable garments prior to storing. Such garments can be treated bysimply immersing them in the cadmium fiuosilicate solution and thenpermitting the solvent to evaporate. So-called dry cleaning would notaffect the fabric treated in this manner. A one- 5. An article ofmanufacture comprising a rub- I berized fabric impregnated with amildewproof- Mixed solvents, such as this tenth of one percent solutionof cadmium fluosilicate will normally introduce a sufilcient protectivequantity in the fabric after the fabric is wetted with it and squeezed,wrung, or centrifuged. Ordinarily, five-hundredths of one percent byweight of elemental cadmium and an equal amount of the fiuosilicate(SiFc) radical will give satisfactory protection.

Having thus described my invention, I claim:

1. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asits essential active ingredient a cadmium containing compound.

2. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asitsessential active ingredient a cadmium salt.

ing agent compatible with rubber, said agent having as its essentialactive ingredient cadmium carbonate. I

6. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asits essential active ingredient cadmium hydroxide.

'7. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asits essential active ingredient cadmium oxide.

8. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asits essential active ingredient cadmium orthophosphate.

9. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asits essential active ingredient cadmium silicate.

10. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asits essential active ingredient cadmium pentachlorophenate.

11. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asits essential active ingredient cadmium naphthenate.

12. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asits essential active ingredient cadmium ortho-phenylphenate.

13. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said' agent havingas its essential active ingredient cadmium chloro-ortho-phenylphenate.

14. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asits essential active ingredientcadmium 2,4,dichloro-ortho-phenylphenate.

15. An article of manufacture comprising a rubberized fabric impregnatedwith a mildewproofing agent compatible with rubber, said agent having asits essential active ingredient cadmium 2,4,dibromo-ortho-phenylphenate.

MARTIN LEATHERMAN.

